http://www.garrysmod.org/downloads/?a=view&id=120052
http://www.youtube.com/flippingwes

An underground test lab abandoned during the war. Many retreated from the lab..all perished. Unlock the secrets of the lab and test your will to continue through the vast halls of uncertainty. Many who painfully died from the radiation linger the halls of the research lab. For now their only purpose is to kill the living. You will not escape..